The time has come for a final report on the 43rd president of the US

The man who set out to reinforce unbridled American power has weakened it in all three essential dimensions

As the two men who would succeed him train like Olympic athletes for tomorrow's foreign policy debate, pause for a moment to complete your final report on the 43rd president of the United States. What would you say?

I would sum up his two terms in four words: hubris followed by nemesis.

Remember the mood music of eight years ago. The greatest power the world has ever seen. Rome on steroids. An international system said to be unipolar, and Washington's unabashed embrace of unilateralism. The US as "Prometheus unbound", according to the neoconservative commentator Charles Krauthammer. Wall Street investment bankers bestriding the financial globe as Pentagon generals did the military globe and Harvard professors the soft power one. Masters of the universe. Personifying that hubristic moment: George Walker Bush.

And now: nemesis. The irony of the Bush years is that a man who came into office committed to both celebrating and reinforcing sovereign, unbridled national power has presided over the weakening of that power in all three dimensions: military, economic and soft. "I am not convinced we are winning it in Afghanistan," Admiral Mike Mullen, chairman of the Joint Chiefs of Staff, told a congressional committee earlier this month. Many on the ground say that's an understatement. The massive, culpable distraction of Iraq, Bush's war of choice, leaves the US - and with it the rest of the west - on the verge of losing the war of necessity. Here, resurgent in Afghanistan and Pakistan, are the jihadist enemies who attacked the US on September 11 2001. By misusing military power, Bush has weakened it.

Economically, the Bush presidency ends with a financial meltdown on a scale not seen for 70 years. The proud conservative deregulators (John McCain long among them) now oversee a partial nationalisation of the American economy that would make even a French socialist blush. A government bailout that will total close to a trillion dollars, plus the cumulative cost of the Iraq war, will push the national debt to more than $11 trillion. The flagships of Wall Street either go bust or have to be salvaged, with the help of government or foreign money. Most ordinary Americans feel poorer and less secure.

The decline in soft power - the power to attract - is also dramatic. The Pew Global Attitudes Survey has recorded a precipitous worldwide fall in favourable views of the US since 2001. The map is chequered, of course, but the distaste extends beyond policies of the Bush administration to things such as "American ways of doing business", and "American ideas about democracy". Iraq has been central to this collapse of credibility and attractiveness. When Bush denounces Russia for invading a sovereign country (Georgia), as he did again at the UN on Tuesday, a cry of "humbug" goes up around the world. Now American-style free market capitalism is taking a further hit, while some of the alternative models are looking better.

Last weekend, five former US secretaries of state - two Democrat, three Republican - gathered for a panel discussion on the future of foreign policy, televised by CNN. Asked by Christiane Amanpour what should be the biggest concern for the new president, Colin Powell replied: "To restore a sense of confidence in the United States of America." Madeleine Albright added that the world of 2009 would be full of issues "that can only be solved in cooperation with other countries". And, Republican and Democrat, they chorussed "close Guantánamo".

Even George Bush now seems to concur with this criticism of George Bush - and I don't just mean speculation that the father is privately critical of the son. Eight years ago, president Bush the younger hardly seemed to know what the word "multilateral" meant. In the course of his farewell address to the UN general assembly this week, he used the word "multilateral" 10 times.

Obviously not all this mess can be blamed on Bush: he's not responsible for the epochal rise of China, nor for jihadist terrorists' long-term hatred of the west.

But a great deal of it can. At the Truman Library in Independence, Missouri, you can still see the painted glass sign that president Harry Truman placed on his desk in the oval office: The Buck Stops Here. (On the back it says: I'm From Missouri.) The buck stops there. The contrast between the president from Missouri and the president from Texas is painful. Judgment, prudence, vision, patience, honesty - every quality that the 33rd president so signally possessed, as the US remade the world after 1945, has been signally lacking in the 43rd.

Iraq, the US's greatest strategic blunder in at least 30 years, is Bush's fault. The buck stops there. And the more we learn about it, the clearer it becomes that it was pursued with a mixture of self-deception and lies. The reporter Ron Suskind has a new book out in which he recounts how, in the runup to war, British intelligence secured unique access to Saddam Hussein's head of intelligence, Tahir Jalil Habbush.

Habbush told them what turned out subsequently to be the truth: that Saddam had ceased his programme of weapons of mass destruction, but would not admit it, because he was obsessed with keeping regional enemies such as Iran in a state of fear and uncertainty. That version was corroborated by Saddam's foreign minister, to whom French intelligence had originally secured access.

The Bush-Cheney White House ignored both reports, preferring what turned out to be the fabrications of a German intelligence source codenamed Curveball. Curveball indeed. Some of Suskind's reporting has been questioned, but the basic story is not in doubt. The Bush-Cheney White House pressed ahead to war on a fraudulent prospectus, suppressing and distorting very important contrary evidence. As a senior member of the administration told Suskind: "We're an empire now, and when we act we create our own reality." Hubris has rarely been better expressed.

Something similar happened with the vertiginous unreality of hyper-leveraged Wall Street investment banking over the past decade. The financiers' motto, too, could have been "We create our own reality". Again, nemesis follows hubris as the night the day. The White House was not directly responsible for what looks like wild financial irresponsibility, but it was responsible for not supervising and regulating it - something even John McCain is now at least implicity admitting. The buck stopped there.

As for the decline in American soft power, that is something for which George Bush was directly to blame. His arrogance, his unilateralism, his insensitivity, his long-time denial of the need for urgent action on climate change: all fed directly into the plummeting credit of the US around the world. It would have been a different story with a different president.

For years now, we have seen those who hate the US abusing and burning effigies of Bush. The truth is, the anti-Americans should be building gilded monuments to him. For no one has done more to serve the cause of anti-Americanism than GW Bush. It is we who like and admire the US who should, by rights, be burning effigies. But now, at last, we live in hope of a better America.